Commit 7ec7096b authored by Pasha Tatashin's avatar Pasha Tatashin Committed by Andrew Morton
Browse files

mm/page_ext: init page_ext early if there are no deferred struct pages 

page_ext must be initialized after all struct pages are initialized. 
Therefore, page_ext is initialized after page_alloc_init_late(), and can
optionally be initialized earlier via early_page_ext kernel parameter
which as a side effect also disables deferred struct pages.

Allow to automatically init page_ext early when there are no deferred
struct pages in order to be able to use page_ext during kernel boot and
track for example page allocations early.

[pasha.tatashin@soleen.com: fix build with CONFIG_PAGE_EXTENSION=n]
  Link: https://lkml.kernel.org/r/20230118155251.2522985-1-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20230117204617.1553748-1-pasha.tatashin@soleen.com


Signed-off-by: default avatarPasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: default avatarMike Rapoport (IBM) <rppt@kernel.org>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Charan Teja Kalla <quic_charante@quicinc.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Li Zhe <lizhe.67@bytedance.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 64517d6e

include/linux/page_ext.h

+2 −0
Original line number Diff line number Diff line
@@ -29,6 +29,8 @@ struct page_ext_operations { 
	bool need_shared_flags;

};



extern bool deferred_struct_pages;



#ifdef CONFIG_PAGE_EXTENSION



/*

init/main.c

+3 −3
Original line number Diff line number Diff line
@@ -855,8 +855,8 @@ static void __init mm_init(void) 
	pgtable_init();

	debug_objects_mem_init();

	vmalloc_init();

	/* Should be run after vmap initialization */

	if (early_page_ext_enabled())

	/* If no deferred init page_ext now, as vmap is fully initialized */

	if (!deferred_struct_pages)

		page_ext_init();

	/* Should be run before the first non-init thread is created */

	init_espfix_bsp();
@@ -1628,7 +1628,7 @@ static noinline void __init kernel_init_freeable(void) 
	padata_init();

	page_alloc_init_late();

	/* Initialize page ext after all struct pages are initialized. */

	if (!early_page_ext_enabled())

	if (deferred_struct_pages)

		page_ext_init();



	do_basic_setup();

mm/page_alloc.c

+5 −1
Original line number Diff line number Diff line
@@ -430,6 +430,8 @@ EXPORT_SYMBOL(nr_online_nodes); 


int page_group_by_mobility_disabled __read_mostly;



bool deferred_struct_pages __meminitdata;



#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT

/*

 * During boot we initialize deferred pages on-demand, as needed, but once
@@ -6803,9 +6805,11 @@ void __meminit memmap_init_range(unsigned long size, int nid, unsigned long zone 
		if (context == MEMINIT_EARLY) {

			if (overlap_memmap_init(zone, &pfn))

				continue;

			if (defer_init(nid, pfn, zone_end_pfn))

			if (defer_init(nid, pfn, zone_end_pfn)) {

				deferred_struct_pages = true;

				break;

			}

		}



		page = pfn_to_page(pfn);

		__init_single_page(page, pfn, zone, nid);

mm/page_ext.c

+1 −1
Original line number Diff line number Diff line
@@ -92,7 +92,7 @@ unsigned long page_ext_size; 
static unsigned long total_usage;

static struct page_ext *lookup_page_ext(const struct page *page);



bool early_page_ext;

bool early_page_ext __meminitdata;

static int __init setup_early_page_ext(char *str)

{

	early_page_ext = true;